'method' : this method was not introduced by 'interface'
When you explicitly override a function, the function signature must exactly match the declaration for the function that you are overriding. For example:
#pragma warning(disable:4199) __interface IX12A { void mf(); }; __interface IX12B { void mf(int); }; class CX12 : public IX12A, public IX12B { void IX12A::mf(int); };